# Script found on KDE-edu list
#
# Look for the header file
# Try to find gnu scientific library GSL
# See
# http://www.gnu.org/software/gsl/ and
# http://gnuwin32.sourceforge.net/packages/gsl.htm
#
# Once run this will define:
#
# GSL_FOUND = system has GSL lib
#
# GSL_LIBRARIES = full path to the libraries
# on Unix/Linux with additional linker flags from "gsl-config --libs"
#
# CMAKE_GSL_CXX_FLAGS = Unix compiler flags for GSL, essentially "`gsl-config --cxxflags`"
#
# GSL_INCLUDE_DIR = where to find headers
#
# GSL_LINK_DIRECTORIES = link directories, useful for rpath on Unix
# GSL_EXE_LINKER_FLAGS = rpath on Unix
#
# Felix Woelk 07/2004
# Jan Woetzel
#
# www.mip.informatik.uni-kiel.de
# --------------------------------

IF(WIN32)
# JW tested with gsl-1.8, Windows XP, MSVS 7.1
SET(GSL_POSSIBLE_ROOT_DIRS
${GSL_ROOT_DIR}
$ENV{GSL_ROOT_DIR}
${GSL_DIR}
${GSL_HOME}
$ENV{GSL_DIR}
$ENV{GSL_HOME}
$ENV{EXTRA}
)
FIND_PATH(GSL_INCLUDE_DIR
NAMES gsl/gsl_cdf.h gsl/gsl_randist.h
PATHS ${GSL_POSSIBLE_ROOT_DIRS}
PATH_SUFFIXES include
DOC "GSL header include dir"
)

FIND_LIBRARY(GSL_GSL_LIBRARY
NAMES gsl libgsl
PATHS ${GSL_POSSIBLE_ROOT_DIRS}
PATH_SUFFIXES lib
DOC "GSL library dir" )

FIND_LIBRARY(GSL_GSLCBLAS_LIBRARY
NAMES gslcblas libgslcblas
PATHS ${GSL_POSSIBLE_ROOT_DIRS}
PATH_SUFFIXES lib
DOC "GSL cblas library dir" )

SET(GSL_LIBRARIES ${GSL_GSL_LIBRARY})

#MESSAGE("DBG\n"
# "GSL_GSL_LIBRARY=${GSL_GSL_LIBRARY}\n"
# "GSL_GSLCBLAS_LIBRARY=${GSL_GSLCBLAS_LIBRARY}\n"
# "GSL_LIBRARIES=${GSL_LIBRARIES}")

ELSE(WIN32)

IF(UNIX)
SET(GSL_CONFIG_PREFER_PATH
"$ENV{GSL_DIR}/bin"
"$ENV{GSL_DIR}"
"$ENV{GSL_HOME}/bin"
"$ENV{GSL_HOME}"
CACHE STRING "preferred path to GSL (gsl-config)")
FIND_PROGRAM(GSL_CONFIG gsl-config
${GSL_CONFIG_PREFER_PATH}
/usr/bin/
)
# MESSAGE("DBG GSL_CONFIG ${GSL_CONFIG}")

IF (GSL_CONFIG)
# set CXXFLAGS to be fed into CXX_FLAGS by the user:
SET(GSL_CXX_FLAGS "`${GSL_CONFIG} --cflags`")

# set INCLUDE_DIRS to prefix+include
EXEC_PROGRAM(${GSL_CONFIG}
ARGS --prefix
OUTPUT_VARIABLE GSL_PREFIX)
SET(GSL_INCLUDE_DIR ${GSL_PREFIX}/include CACHE STRING INTERNAL)

# set link libraries and link flags
EXEC_PROGRAM(${GSL_CONFIG}
ARGS --libs
OUTPUT_VARIABLE GSL_LIBRARIES)

# extract link dirs for rpath
EXEC_PROGRAM(${GSL_CONFIG}
ARGS --libs
OUTPUT_VARIABLE GSL_CONFIG_LIBS )

# split off the link dirs (for rpath)
# use regular expression to match wildcard equivalent "-L*<endchar>"
# with <endchar> is a space or a semicolon
STRING(REGEX MATCHALL "[-][L]([^ ;])+"
GSL_LINK_DIRECTORIES_WITH_PREFIX
"${GSL_CONFIG_LIBS}" )
# MESSAGE("DBG GSL_LINK_DIRECTORIES_WITH_PREFIX=${GSL_LINK_DIRECTORIES_WITH_PREFIX}")

# remove prefix -L because we need the pure directory for LINK_DIRECTORIES

IF (GSL_LINK_DIRECTORIES_WITH_PREFIX)
STRING(REGEX REPLACE "[-][L]" "" GSL_LINK_DIRECTORIES ${GSL_LINK_DIRECTORIES_WITH_PREFIX} )
ENDIF (GSL_LINK_DIRECTORIES_WITH_PREFIX)
SET(GSL_EXE_LINKER_FLAGS "-Wl,-rpath,${GSL_LINK_DIRECTORIES}" CACHE STRING INTERNAL)
# MESSAGE("DBG GSL_LINK_DIRECTORIES=${GSL_LINK_DIRECTORIES}")
# MESSAGE("DBG GSL_EXE_LINKER_FLAGS=${GSL_EXE_LINKER_FLAGS}")

# ADD_DEFINITIONS("-DHAVE_GSL")
# SET(GSL_DEFINITIONS "-DHAVE_GSL")
MARK_AS_ADVANCED(
GSL_CXX_FLAGS
GSL_INCLUDE_DIR
GSL_LIBRARIES
GSL_LINK_DIRECTORIES
GSL_DEFINITIONS
)
MESSAGE(STATUS "Using GSL from ${GSL_PREFIX}")

ELSE(GSL_CONFIG)
MESSAGE("FindGSL.cmake: gsl-config not found. Please set it manually. GSL_CONFIG=${GSL_CONFIG}")
ENDIF(GSL_CONFIG)

ENDIF(UNIX)
ENDIF(WIN32)


IF(GSL_LIBRARIES)
IF(GSL_INCLUDE_DIR OR GSL_CXX_FLAGS)
SET(GSL_FOUND 1)
ENDIF(GSL_INCLUDE_DIR OR GSL_CXX_FLAGS)
ENDIF(GSL_LIBRARIES)

